RunFlat tyres: features, types, manufacturers
Neither an experienced, nor a new driver is immune to tyre punctures. This can be a real problem as driving on a flat tyre isn’t allowed. If you have no spare tyre or special tyre repair kit, or in case, for example, you have two tyres punctured at a time, you have to call for a tow service. The situation when a tyre blows out at a high speed is even worse: you can lose control over your vehicle. RunFlat tyres will help to avoid these troubles. Here we tell you what they are and what are their advantages and disadvantages.
What RunFlat is: construction, history, marking
The RunFlat technology is aimed at minimizing the risk of a car accident and allowing a driver to get to a car service station. In addition, if you use this kind of tyres you can do without a spare tyre to save space or reduce fuel consumption.
Development of safe tyres protected from blowing out started in the 1930s. The Michelin company became a pioneer in this field. In 1934 they introduced the world’s first self-supporting tyre with a special foam lining inside which took the load in case of puncture. The idea to create a puncture resistant tyre was picked up by Chrysler, Goodyear, Dunlop, and other manufacturers.
Today RunFlat tyres are offered in the product range of all leading manufacturers. Such tyres can be marked differently. For example, as follows:
- Dunlop ― DSST.
- Pirelli, BridgeStone, Firestone ― RFT.
- Nokian ― RFT and RF.
- Yokohama ― RF and ZPS.
- Continental ― SSR and CSR.
- Michelin ― ZP.
- Goodyear ― ROF and EMT.
- BF Goodrich ― SSS.
- Kumho ― XRP.
- Toyo ― TRF.
Types of RunFlat tyres, their advantages and disadvantages
- Self-sealing. They have a layer of sealant inside which seals the puncture. These tyres are just 10–20% more expensive than conventional ones. They can be installed on cars not equipped with a tyre pressure monitoring system. These tyres can be repaired after puncture. However, they aren’t capable of maintaining pressure in case of large cuts or if the sidewall is punctured. Efficiency of self-sealing is reduced in cold season.
- With reinforced sidewalls. Their sidewalls consist of a few layers of a special cord and rubber. It is they that take all the load in case of puncture. Such tyres are high-strength and wear-resistant. Their cost is about 1.5–2 times higher than that of conventional tyres. These tyres are installed on a standard wheel rim and allow you to cover up to 80 km after puncture. However, the speed of the vehicle should be below 80 km/h. In addition, these tyres are 20–40% heavier than standard ones. In most cases they are not repairable.
- With a support ring. A special plastic or metal ring is attached to the wheel rim and it holds the car’s weight in case of pressure loss. Such tyres allow for travelling up to 320 km. They don’t limit the vehicle speed even after puncture. These tyres are often installed on armoured cars, like official state vehicles. They are expensive. Moreover, their use requires installation of special wheel rims. These tyres can only be mounted at specialized service stations. Their use reduces the driving comfort.
Who will find RunFlat tyres a good choice
Not every driver will appreciate the advantages of these tyres. If comfort and dynamics are a top priority for you, then you should give preference to standard tyres. But if you value reliability and practicality, often make off-road or long trips, this kind of tyres can be of real help for you.
